Maybe some people in here can make suggestions. This guy is well respected, a fellow moderator, and talented at seo and marketing in general. I think his prices are up there, but quality costs.
Still ... you really won't get the same quality advice without posting some more detail. What's your site? What keywords are you targeting? What are your goals?
I'll second that. Its worth paying for someone with a track record rather than just buying on price. Search engine results are dynamic and the rankings change all the time. For this reason I always tell people that although they should pay for quality, they should also be prepared to spend more than just once. Search engine optimisation is an ongoing task not one off hit.